title: Biochemical markers of bone metabolism in postmenopausal women--the effect of hormone replacement therapy and smoking.
abstract: OBJECTIVE
  Investigation of biochemical markers of bone metabolism in postmenopausal women with respect to hormone replacement therapy and smoking as a risk factor for osteoporosis.
  
  
  METHODS
  Cross-sectional study of 107 healthy women receiving hormone replacement therapy (24 smokers) and 50 postmenopausal women (20 smokers) who served as a control group. The following biochemical parameters were analyzed in the serum: total calcium, inorganic phosphate, total alkaline phosphatase, procollagen I C-terminal propeptide (PICP), and cross-linked carboxyterminal collagen I telopeptide (ICTP). The effect of hormone replacement therapy and smoking on biochemical parameters was assessed by a two-way ANOVA.
  
  
  RESULTS
  Significantly lower values of total calcium, inorganic phosphate, alkaline phosphatase, and ICTP in women on hormone replacement therapy compared to the control group indicated a higher rate of bone remodeling in the untreated postmenopause. In women smokers versus non-smokers, significantly lower values of only ICTP were found. Both hormone replacement therapy and smoking affected total calcium and phosphate levels, with the lowest values in non-smoking women on hormone replacement therapy and the highest in non-smoking control women.
  
  
  CONCLUSIONS
  Reduction of bone turnover by hormone replacement therapy in menopause was indicated by lower values of biochemical parameters and collagen-related bone markers. Hormone replacement therapy is the prevalent factor affecting biochemical parameters, and probably conceals the possible effect of smoking.
authors.affiliation: Clinical Institute of Laboratory Diagnosis, Zagreb University Hospital Center, Kispaticeva 12, Zagreb, 10000, Croatia. rkusec@oddy.irb.hr
authors.forename: V
authors.initials: V
authors.lastname: Kusec
authors.forename: A
authors.initials: A
authors.lastname: Stavljenić Rukavina
authors.forename: M
authors.initials: M
authors.lastname: Cubrilo Turek
mesh_terms: D001842:Bone and Bones / Q000378:metabolism*; D003430:Cross-Sectional Studies; D015914:Estrogen Replacement Therapy; D005260:Female; D006801:Humans; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000209:etiology / Q000378:metabolism / Q000517:prevention & control; D017698:Postmenopause / Q000378:metabolism*; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*